The Food and Drug Administration staff said agency advisers
meeting on the devices this week should consider when and how
patients should undergo imaging and ion testing to measure the
metal’s effect on surrounding tissue, according to documents
posted on the agency’s website today.

The Food and Drug Administration will convene an advisory
panel meeting June 27 and 28 to discuss the implants, which have
been the subject of thousands of patient lawsuits. The metal
devices have been linked to almost 16,800 adverse events in the
U.S. from 2000-2011, regulators said in a report last week.

“In general, the overall use of metal-on-metal has
diminished quite a bit,” Matthew Taylor, an analyst with
Barclays Capital Inc., said by telephone. “Physicians are
cautious about using these.”

The DePuy unit of New Brunswick, New Jersey-based J&J began
recalling hip devices in 2010, after more than 12 percent failed
within five years. About 74 percent of 12,137 incident reports
to the FDA in 2011 involved that device, the agency reported.

J&J faces more than 6,000 lawsuits related to the metal-on-
metal hips in federal and state courts. In May 2011, the FDA
asked hip implant makers to conduct post-market studies.

While the majority of patients with the implants do well,
surgeons need to know what to do if they exhibit high levels of
metal in their blood, said Joshua Jacobs, a surgeon and vice
president of the American Academy of Orthopaedic Surgeons, in a
telephone interview. Metal ions can damage tissue and require
revision surgery to replace the old device.

Imaging Role

The FDA’s advisers have been asked to consider the role of
imaging in patients who exhibit signs of problems and those that
don’t. They will also weigh who should be tested for metal ion
levels, and how the result would be used by the physician.

“Soft tissue imaging of the hip may be the most effective
means to identify a soft tissue reaction in a patient,” FDA
staff said in the document.

Metal-on-metal hip implant use peaked in 2006 and 2007 at an
estimated 30 percent of the market and is now about 10 percent,
Barclay’s Taylor said. Other implants include those made of
ceramic and polyethylene. The ball and socket are each made of
metal on the implants in question.

Adverse Events

Adverse event reports in 2011 totaled 12,137 for the metal-
on-metal devices, compared with 6,332 associated with other
types of hip implants, according to an FDA document. The most-
reported side effect was revision, meaning surgery to remove or
replace the implant. Revisions totaled 14,131 in metal-on-metal
hip implants followed by 8,704 reports of pain.

FDA staff assessed all available literature to attempt to
compare metal implants to the other versions and determined the
rate of replacement surgery for metal implants “is likely not
lower” than the rate associated with other implants, according
to the documents posted today.

A review of international and U.S. registries also found
higher rates of revisions for metal implants. The national
registry in England and Wales found the rate of replacement
surgeries after five years for metal-on-metal implants was 6.2
percent, almost three times as high as other versions. A
registry of implant procedures in Minneapolis and St. Paul,
Minnesota, established by provider HealthEast Care System found
metal-on-metal systems were associated with a four times higher
occurrence of revision surgeries than metal and polyethylene.

If the FDA restricts metal-on-metal implants, companies
such as Biomet Inc., based in Warsaw, Indiana, won’t be
significantly affected, Taylor said.

“Most of the companies have a full line of hip products
they can sell so they’d just be swapping it out with the other
hip products,” he said.